Bird Technologies 4391A - Manual (Page 34)

22
Disassembly
Display
indicates “0”
Power Element wiper not
contacting the element Readjust the
element wiper to
make good contact.
Defective Plug-in
Element Replace Plug-In
Element.
Defect on Data
Acquisition PC board
assembly Replace the PC
board assembly
(attached to line
section).
One
segment of a
display does
not light Defective Display Replace the display.
All decimal
points stay lit Low charge on the
batteries Recharge the
batteries.
Defective circuit
component Replace the Main
circuit board
assembly.
Same
segment on
all displays
doesn’t light Defective circuit
component Replace the Main
circuit board
assembly.
One or more
keys do not
function Defect on Main PC
board Replace the Main
circuit board
assembly.
WARNING
Be sure that the power cable is unplugged before opening
the wattmeter case. The power supply capacitor, C1, can
retain a dangerous charge that must be removed before
touching. Always have another person standing by who is
trained in electric shock first aid.
CAUTION
This instrument contains static sensitive electronic
components. Before opening or servicing the unit, make
sure that you understand and practice electrostatic
discharge component handling. Failure to comply may result
in permanent damage to sensitive components.
PROBLEM POSSIBLE CAUSE REMEDY